This invention relates to disposable diapers provided with adhesive tab fasteners, and particularly tab fasteners of the extensible type useful for diaper closure and in other applications.
Extensible diaper tabs have previously been proposed as a means to improve the fit of the diaper by utilizing the diaper tabs as elastic extensible side waistbands.
An early proposal is that of U.S. Pat. No. 3,800,796 to Jacobs. Later improvements or alternatives to the early Jacobs concept of an extensible tab include U.S. Pat. No. 4,051,853 to Egan and U.S. Pat. No. 4,066,081 to Schaar.
One problem with extensible tabs is the need to avoid premature stretching prior to initial fastening of the diaper, and particularly to stabilize (avoid stretching) the stretchable part of the tab material, so as to allow accurate placement of tabs on the diaper, even under the inertia stresses associated with the high line speeds that are necessary for economical manufacture. One approach to this problem of premature extension is shown in U.S. Pat. No. 4,389,212 to Tritsch. In this approach, a breakable "attachment portion" 40 (FIG. 3), 140 (FIG. 6), or 240 (FIG. 7) provides temporary stabilization. This "attachment portion" appears to be a weakened joint in the midsection of the tab, which joint is not completely parted until the end user fastens the diaper. Tritsch does not disclose how such a weakened joint is formed, nor how it is conditioned to resist breaking under high inertia stresses during diaper manufacture and yet part readily and conveniently when the diaper and its tabs are deployed to diaper a baby.